The present invention relates to a method of manufacturing a molded connector for forming a molded connector by subjecting a synthetic resin material to secondary molding on the outer sides of a primary molded piece having terminal portions, as well as a primary molded piece for the molded connector.
FIG. 7 shows an example of a related molded connector (see Japanese Patent Publication No. 8-2501 93A).
This molded connector 90 is comprised of a primary molded piece 97 formed by insert-molding terminals 91 through a synthetic resin-made core 92, a soft sealant 93 filled in a recessed portion of the core 92 and adhering to the peripheries of the terminals 91, and a synthetic resin-made connector housing 94 covering the outer sides of the primary molded piece 97. The core 92, the sealant 93, and the connector housing 94 have insulating properties, respectively.
The terminals 91 are arranged in two stages in face-to-face relation, and distal end portions of the terminals 91 are projectingly positioned in connector engaging portions 95 and 96 on both sides of the connector housing 94. For example, a connector portion (not shown) of an apparatus or the like is connected to one connector engaging portion 96, while a connector (not shown) on the wire harness side is engaged with the other connector engaging portion 95. Since the terminals 91 are passed through the sealant 93, the penetration of water or the like from one connector engaging portion 96 to the other connector engaging portion 95 can be prevented.
As for the method of manufacturing this molded connector 90, the plurality of terminals 91 are first insert-molded together with the core 92 which is a synthetic resin material, thereby obtaining the primary molded piece 97. Insulation is provided for the terminals by the core 92, and the positioning of the terminals with respect to each other is effected. Next, the sealant 93 is filled in the recessed portion of the core 92 of the primary molded piece 97. Then, the primary molded piece 97 is set in a mold (not shown), a resin material is injected over the primary molded piece 97 to form the connector housing 94, thereby obtaining the molded connector 90 which is a secondary molded piece.
The reason for performing primary molding (preliminary molding) is to prevent the short-circuiting of the terminals 91 due to the occurrence of the positional offset of the terminals 91 by being pressed by the resin pressure, and partly because the terminals 91 cannot be left exposed since a waterproofing structure is adopted.
However, with the above-described related method of manufacturing a molded connector, there have been apprehensions that the primary molded piece 97 is liable to become deformed (the core 92 becomes soft and is liable to become deformed since molding is effected at a high temperature) by being pressed by the high resin pressure during secondary molding (final molding), and that, particularly in the molded multi-way connector using the multiplicity of terminals 91, short-circuiting can occur due to the offset of the positions of the terminals 91 or the contacting of the terminals, and durability deteriorates due to the occurrence of large stresses and strains in the core 92 of the synthetic resin material, with the result that cracks are liable to occur.
For this reason, molding conditions are determined during secondary molding to position and fix the primary molded piece 97, but much man-hour has been required for the management of the positioning and fixation of the primary molded piece 97, and much inspection man-hour has been required for performing continuity checks for the total number of the terminals to ensure the perfection of production quality.
In view of the above-described problems, the object of the invention is to provide a method of manufacturing a molded connector and the structure of a primary molded piece which make it possible to easily and reliably inspect an inferiority such as deformation of the primary molded piece during secondary molding.
In order to achieve the above object, according to the present invention, there is provided a method of manufacturing a molded connector formed by a primary molding and a secondary molding, comprising the steps of:
preparing a primary molded piece having resin portion integrally formed with terminals and a projection formed on the resin portion;
disposing the primary molded piece inside a mold used for the secondary molding such that a distal end face of the projection abuts against a part of inner face of the mold;
injecting resin material into the mold to conduct the secondary molding; and
removing a formed secondary molded piece from the mold.
The projection is deformable in accordance with inspecting pressure of the resin material.
Preferably, the manufacturing method further comprises inspecting a shape of the distal end face of the projection after the secondary molded piece is removed from the mold to judge inferiority of inspecting pressure of the resin material. Here, it is judged that the injecting pressure is inferior when a cross section area of the inspected distal end face increases in comparison with an initial cross section area thereof at a predetermined rate.
Therefore, for example, as the operator confirms the shape of the distal end face of the deformable portion, it is possible to easily and reliably detect an inferiority in the resin pressure and deformation of the primary molded piece. Thus, since an inferiority such as the positional offset of the terminal portions of the primary molded piece and cracks in the resin portion can be easily and reliably detected, it is possible to reduce the man-hour required in the management of the positioning and fixation of the primary molded piece and to detect an inferiority without resorting to the continuity check of the terminal portions. In addition, it is also possible to detect even slight inclination of the terminal portions, so that inspection accuracy improves.
Preferably, a gate for injecting the resin material is provided on a line extending along and through the projection.
Accordingly, since the pressing force based on the resin material injected from the gate is directly transmitted to the projection, the sensing accuracy of the deformable portion is enhanced, and the deformable portion reliably undergoes crushing deformation even with respect to slight abnormal pressure, thereby making it possible to more reliably detect an inferiority such as the deformation of the primary molded piece.
Preferably, the mold has a positioning member for supporting the resin portion when the primary molded piece is disposed therein. The primary molded piece includes an engagement member for engaging with the positioning member.
Accordingly, the primary molded piece is stably supported by the positioning member and the projection, so that the positioning and fixing accuracy of the primary molded piece inside the mold is enhanced.
Preferably, the positioning member extends perpendicular to an extending direction of the projection of the primary molded piece.
Accordingly, the primary molded piece can be supported from two-dimensional directions by the positioning member and the projection, so that the positioning and fixing accuracy of the primary molded piece is further enhanced.
Preferably, the projection is rib-like member longitudinal direction of which is perpendicular to an extending direction of the terminals.
Accordingly, as the elongated rib member undergoes crushing deformation, the distal end face of the rib member is expanded in its widthwise direction, so that the operator and a camera of an automated machine is able to easily detect the deformation of the distal end face, thereby rendering the inspection easier and more reliable.